Stage 4 prostate cancer treatment options

I have recurring prostate cancer and it has found its way to 5 different bones, including my left shoulder and two ribs on my right side. I started 6 month Lupron shots but have been told that because it is stage 4 I need additional treatment. My oncologist is recommending either Abiraterone (Zytiga) for 33 months or 6 treatments of Docetaxel chemo. She says that they look to have very equal success. With the Zytiga I will also have to take steroids, probably prednisone which I understand includes possible liver damage. Six chemo treatments seems like a better approach but I have heard Zytiiga talked about in a very positive manner. I understand it can be expensive and I do worry my prescription drug coverage could change its formulary and raise my cost significantly as well. I've already had that happen with a drug I take for Parkinsons.. Just looking for some general input regarding peoples actual experience either way.